Steve,

Is the copper current swithed off after the required time or reduced to a very 
low trickle. We shut down the rectifier at the end of the copper cycle although 
a strike voltage does not cause adhesion problems, only dull copper. To see if 
there is an electrical problem, try leaving some dummy panels in the copper 
solution after plating and see whether any organic or oxide film forms.

Do the solutions need carbon treament? Polymers leached from the dry film can 
redeposit on the copper surface under certain circumstances.

I cannot think of anything in the tin-lead which could cause this problem. We 
put a small amount of lead fluoborate in our pre-dip to drop out any sulphates 
which might carry over.
-- 
Paul Gould
Teknacron Circuits Ltd
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